There are four species of widow spiders that you might find in Florida; three of them native and one of them introduced.
- Southern Black Widow (Latrodectus mactan)
- Northern Black Widow (Latrodectus various)
- Red Widow (Latrodectus bishopi)
- Brown Widow (Latrodectus geometricus)
Typically, a female widow spider has a glossy, jet black body and a bright red mark on the underside of her abdomen that is shaped like an hourglass. The males are usually gray or brown. The females are much bigger than the males, with the females measuring around 1.5 inches and the males being only a quarter of the size.
The female widow is the most poisonous of the two genders, as its venom sacs are much bigger. The bite of the male is not generally considered to be dangerous.
Widow spiders are nocturnal and build irregular, tangled, three dimensional webs, where they rest during the daytime. Widows will often hang upside down near the center of the web, until they detect an insect getting caught (usually by sensing vibration, rather than by sight), when they will run over and bite the insect, then cover it in silk.